The invention relates to a suspension for a front, especially a transversely mounted, motor vehicle power plant that is arranged in a frame structure on a mount located forward of the engine and laterally and rearwardly on resilient mounts.
On head-on collision of a vehicle provided with a front engine, at least above a certain speed, the mounts of the vehicle power plant, which may be an engine or engine-transmission unit, are destroyed. To avoid an undesirable impulse transmission from the power plant to the body, these mounts are usually relatively soft. As a result of the destruction of the mounts on impact, the power plant moves toward the vehicle occupant compartment after the vehicle has collided.
German Patent Application (Auslegeschrift) No. 2,455,790 reveals an arrangement for mounting a motor vehicle front power plant on resilient mounts. This arrangement is retained by a bracket which absorbs the deformative action rearward of the plant, at the central tunnel of the body structure. Also known are longitudinal support members constructed as deformation elements of body structures (U.S. Pat. No. 3,869,017), and deformation elements mounted on the front transverse member of a bumper structure (German Patent Application--Offenlegungsschrift--No. 2,757,421). It is also known (German Patent Application--Offenlegungsschrift--No. 2,249,555) to construct a mount arranged rearwardly of the power plant so that it breaks off when a certain critical impact load is exceeded. Then the power plant falls down uncontrolled. Other known suspensions (German Patent Application--Offenlegungsschrift--No. 2,056,102) for power plants are constructed to deflect the plant toward the roadway on collision.
The object of the invention is to supply a vehicle power plant suspension in which a mount provides for the absorption of sufficient deformation and a functionally adapted relative motion of the plant or frame without destruction of the other mounts.
According to preferred embodiments of the invention, this object is achieved with the power plant being carried on the vehicle body by an energy-absorbing front longitudinal support and at least one mount constructed as a slide mount to permit relative motion between the power plant and the vehicle body.
The advantages derived from the invention include the provision, substantially above the front and rear mounts, of an oscillation-engineering based front power plant suspension which simultaneously permits the relative motions of the plant toward the body and the relative motions of the body toward the plant on vehicle collision, without immediately destroying the rear mount. For this purpose, the front mount support is constructed as a deformation element which is capable substantially of absorbing kinetic energy along its entire length in the longitudinal direction of the vehicle. Beside its deformability, the front support is constructed primarily to absorb the static and dynamic bending forces applied by the plant and the impulses of motion.
The structure of the front mount permits separate adjustment, depending on the desired strength and crash behavior. Thus, the energy absorption capacity of the support is made possible almost without alteration of the strength by the introduction of additional deformable elements.
The rear mount is in the form of a thrust and compression bearing, provides for the soft absorption of the bearing forces, acts as a torque support, and allows freedom of motion to the power plant when a collision occurs in the longitudinal direction of the vehicle. For this purpose, the bearing is constructed so that the support arm can penetrate the bearing housing.
Since the front and rear mounts are located along the line of mass of the plant, the third, laterally located mount has only a support function, and, therefore, can be simply constructed. It is connected to the power plant transmission by a support which is relatively soft in the longitudinal direction of the vehicle and readily deformed on frontal impacts, so that it has little effect on the longitudinal supports of the body structure.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.